Percent of Change 7.RP.3 Use proportional relationships to SOLVE multi-step ratio and percent problems. Examples: simple interest, tax, markups and markdowns, gratuities and commissions, fees, percent increase and decrease, percent error. 1

What is Percent of Change? Common Examples of Percent of Increase Common Examples of Percent of Decrease Sales tax on an item purchased Items that are on sale at a store Finding a total bill at a restaurant including tip Population decreases

Percent of Change Percent of Change: the amount, stated as a percent, that a number increases or decreases. Percent of Increase: The amount, stated as a percent, that a number goes up. Percent of Decrease: The amount, stated as a percent, that a number goes down.

Percent of Change Percent of Change = amount of change original amount

Finding Percent of Change 27 is decreased to 20 27 – 20 = 7 Percent of Change = amount of change original amount Percent of Change = 7 27 Percent of Change ≈ 0.259259 Percent of Change ≈ 25.9%

Finding Percent of Change 32 is increased to 67 67 – 32 = 35 Percent of Change = amount of change original amount Percent of Change = 35 32 Percent of Change ≈ 1.09375 Percent of Change ≈ 109.4%

Finding Percent of Change 20 is decreased to 11 20 – 11 = 9 Percent of Change = amount of change original amount Percent of Change = 9 20 Percent of Change ≈ 0.45 Percent of Change ≈ 45%

Finding Percent of Change 42 is increased to 72 72 – 42 = 30 Percent of Change = amount of change original amount Percent of Change = 30 42 Percent of Change ≈ 0.71428 Percent of Change ≈ 71.4%

Finding Percent of Change Your Turn… 24 is increased to 30 Percent of Change = amount of change original amount

Finding Percent of Change Your Turn… 56 is decreased to 14 Percent of Change = amount of change original amount

Finding Percent of Change Your Turn… 105 is decreased to 32 Percent of Change = amount of change original amount

Finding Percent of Change Word Problems Zack Cole shot an 86 on the golf course on Monday. On Friday he shot a 95. What is the % of change? 86 increased to 95 Percent of Change = amount of change = 9 original amount 86 Percent of Change = 10.5%

Finding Percent of Change Word Problems Kelly Dyer became a great writer. She had a picnic each year to celebrate the date of her first published work. The 1st year 50 people came. The 2nd year 30 people came. What is the percent of change? 50 decreased to 30 Percent of Change = amount of change = 20 original amount 50 Percent of Change = 40%

Finding Percent of Change Word Problems: Your Turn Jack bought a stereo on sale for $231. The original price was $385. What was the percent of decrease in price?

Finding Percent of Change Word Problems: Your Turn Angela Smyre became a famous architect. She made $90,000 in 2004. In 2005 she made $120,000. What is the percent of increase?

Finding Percent of Change Word Problems: Your Turn Amber Robinson became a foster mother, because she is so good with children. She took care of 8 children in 2003. In 2004 she had only 5. What is the percent of decrease?